Vehicles such as cars or motorcycles are usually equipped with a battery in order to provide electric power. When a user is driving a car or riding a motorcycle, the operating engine of the car or the motorcycle would charge the battery. When the car or the motorcycle consumes electricity, for example to start the motor, the headlight, the car stereo system, the air conditioner, etc, electric power is supplied by the battery.
If a driver forgets to turn off the headlight, the night light, or any other electric device on a vehicle which consumes electricity before leaving the vehicle, the electric power of the battery may be exhausted and the vehicle may be unable to start because the battery continues to provide electricity without being charged. When this happens, a driver may activate the vehicle with the help of another vehicle's battery. This, however, requires a power line to connect the two batteries. Furthermore, the power line needs to be connected to the correct electrodes of the two batteries; otherwise there may be risk of short circuit.
Emergency vehicle rescue device has been invented, which includes an electric circuit for automatically detecting the electrode of a vehicle battery. When a vehicle battery is over-discharged and cannot be started, the emergency vehicle rescue device may be used to electrically connect the two conductive terminals of the battery and provide enough power for the vehicle to start.
However, the above-mentioned emergency vehicle rescue device has the following problems and disadvantages:
Because the relay is characterized of high current loading, a control circuit of such emergency car emergency rescue device uses relay as a switch for the emergency car rescue device to power the vehicle battery. When the user connects an anode connection line and a cathode connection line of the emergency car rescue device respectively to an anode end and a cathode end of the vehicle battery, the relay is turned on to power the vehicle battery. But when the user takes the anode connection line and the cathode connection line of the emergency car rescue device away from the anode end and cathode end of the vehicle battery, then the relay keeps being turned on.
However, when the relay keeps being turned on and is not able to be reset, if the user connects the anode connection line and the cathode connection line of the emergency car rescue device respectively to the anode end and the cathode end of the vehicle battery again, because the relay keeps being turned on, then spark may happen on the relay because of the large instant current, and the lifetime of the relay would thus decrease. Further, if the user connects the anode connection line and the cathode connection line of the emergency car rescue device respectively to the cathode end and the anode end of the vehicle battery, this is incorrect connection, because the relay keeps being turned on and powers the wrong vehicle battery, the dangerous short is happened.
To solve the aforementioned problem, it is thought about how the relay is reset to be closed when the user takes the anode connection line and the cathode connection line of the emergency car rescue device away from the anode end and cathode end of the vehicle battery. In the existing technology, two methods: hardware reset and software reset are often used. Wherein, in the hardware reset, a manual switch is disposed in the emergency car rescue device. When the user switches to the manual switch, the relay is reset. However, though the method indeed can solve the problem of the reset of relay, but it is not intuitive and humanized enough. While in the software reset, an automatic program is programmed in a micro processor of the control circuit, in order to set the relay to reset a time per few seconds by the program, such as two seconds. However, although the method naturally solve the problem of resetting the relay, the user does not need to operate manually. But when the user connects the anode connection line and the cathode connection line of the emergency car rescue device to the vehicle battery in two seconds, the same problem as mentioned above is happened.
Therefore, it is an purpose for the inventor and the skilled people in the field to research in order to improve, and solve the problem and disadvantage of the prior art.